Help! Which bike to buy??!!??

With just turning 30, I have decided to upgrade my basic alu framed/veloce 2008 road bike that serves as my only bike. Looking around the best deal appears to be the Planet X SL pro carbon. Would people recommend carbon over aluminium (currently tipping the scales @ 90kg)?
Is the SRAM red version worth the extra £300 over rival? Are there any other bikes around the £1000-1300 mark that people would recommend over the Planet X??

Sorry for all the questions, been looking for about 2 months and always seem to come back to the Planet X, just need to get up there and have a look!

In fairness in that pricerange I don't think theres much difference between carbon and aluminium. Mind though that aluminium will allow for more flex than carbon which I would imagine would make a difference at your weight. But thats an assumption, and not science, so don't take my word for it!

clearance cannondale, got a caad 10 for 899. stunning, i have a decent selection of bikes and have had various ones over the years, the cannondale is beyond fast its amazing. very light as well, c/p weighed the frame at 1200g the fork 410g. the other carbons tested around it were lowest of 1100g frame and same on the forks. a great platformt to build on(whichi have done)